DevHeads.net

Postings by Chuck Campbell

Certificates

I am getting myself confused, and need someone who fully understands
this process to help me out a bot.

I would like to obtain an ssl certificate, so I can run my own imap
server on a machine in my office.

My domain is hosted by networksolutions, but I don't run my imap server
there.

I am assuming I'll need to pay a CA to generate what I need, but I'm
confused about what I need. I am running dovecot at teh moment, but my
clients (iphone, windows laptops) say my ssl connection is not trusted.

elrepo kmod-nvidia issue with update

when I do yum update, elrepo offers kmod-nvifdia, but yum does this:

--> Processing Dependency: kernel(sme_me_mask) = 0x17fbce60 for package:
kmod-nvidia-390.48-2.el7_5.elrepo.x86_64
--> Processing Dependency: kernel(reservation_object_add_excl_fence) =
0xea98efc0 for package: kmod-nvidia-390.48-2.el7_5.elrepo.x86_64
--> Processing Dependency: kernel(drm_vblank_init) = 0xdcd50a49 for
package: kmod-nvidia-390.48-2.el7_5.elrepo.x86_64

.

.

.

repeatedly, then says:

 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

Is the

Named log question

Is this mis-configuration, or just noise in my log?

    29-Apr-2018 00:50:26.056 general: warning: managed-keys-zone: No
DNSKEY RRSIGs found for '.': success: 1 Time(s)
    29-Apr-2018 00:50:26.120 general: warning: managed-keys-zone: No
DNSKEY RRSIGs found for 'dlv.isc.org': success: 1 Time(s)

-chuck

Postfix config problem w/ tls

I have followed the guides on setting up postfix relay to my account at
network solutions.

I added these to main.cf:

inet_interfaces = localhost

relayhost = [mail.mydomain.com]:587

smtp_sasl_auth_enable = yes
smtp_sasl_security_options = noanonymous
smtp_sasl_password_maps = hash:/etc/postfix/sasl_password
smtp_use_tls = yes
smtp_tls_CAfile = /etc/pki/tls/certs/sendmail.pem

The username and password are correct, and all these options work fine
from thunderbird on a windows box in my local network.

I get no errors on postfix restart, but when I try to send an email from
the centos box,

upgrade reference docs

Is there a Centos 6.x to Centos 7.x guide somewhere? What has changed, that I
need to learn about as an admin, before I jump in and flounder?

thanks,

-chuck

firefox 38 question

Is Firefox 38 still borked for Centos 5?

It shows up as available for update, but I don't recall seeing anything saying
the problems noted here have been fixed.

thanks,
-chuck

disk order question

I'm not sure, but I think I may be having a disk order issue related to my installation woes.

When I boot the installer, it sees /dev/sda and /dev/sdb on my 3ware disk controller (both multi TB raid 5 arrays). It also sees /dev/sdc, which is the target disk for the installation.
The install runs fine (5.11, BTW) and tells me to reboot.

install woes

I'm really at a loss.
I had 5.11 running on this machine, from this physical boot disk, until I
stepped on /bin the other day.

I've tried installing Centos 5.10 and 5.11 to this Seagate 1TB drive. Both
installs run perfectly, but when I try to reboot, grub says
Filesystem type unknown, partition type 0xee

googling this indicates that the disk has a GUID partition table. This must have
been done by the installer??? If so, why doesn't it get the boot loader set up
correctly?

Sigh,

So stage two of the saga, I thought I would try to install CentOS 6.5 (I had the
dvds burned already).

how can I tell what's on the MBR of /dev/sda?

Subject says it.

I would like to find out if I have anything written on the MBR of a disk
in my system /dev/sda, or any other device.
If there is something there, is it readable, or recognizable to humans?

thanks,
-chuck

install problem

I shot myself in the foot today. I had a centos 5.11 install running fine. Doing
a backup, I overwrote the /bin directory by mistake.

I couldn't get my machine to recognize a centos 6.5 or 6.6 install dvd, so I put
in the original centos 5.10 install disc and re-installed. No problem. During
the text installer, I told it to install grub on /dev/sdc1, which is /boot.

6.5 install dvd won't

When I boot a machine from disc 1 of 2, Centos 6.5 install dvd, I get to a grub
prompt.

I have no idea what to do from there, but clearly something isn't right.
Shoudl I try to download centos 6 again and burn new discs?

thanks,
-chuck

move a disk to another machine

I have a centos 6.6 laptop which is having trouble (intermittent boot failures,
or more rightly so, multiple failures, intermittent booting). The laptop is
running selinux.
I pulled the second internal disk out to get my data off of it. I plugged it
into my centos 5.x machine and mounted it. I was able to do a dir listing, but
whrn I tried to cd into any of the directories, I get a bunch of AVC denials,
and I can't see any files. The contos 5.x machine is selinux enforcing, and so
is the centos 6.x box.

dovecot move doesn't work

I'm running centos 6.6 with the default 2.0.9-xxx dovecot.

I run sa-learn against my spam_to_learn folder, then I wan to move those emails
to a learned_spam folder.
when I do a doveadm -Dv move -u user learned_spam mailbox 'spam_to_learn' ALL

I get this result:
usage: doveadm [-Dv] [-f <formatter>] <command> [<args>]

altmove [-u <user>|-A] [-S <socket_path>] <search query>
auth [-a <auth socket path>] [-x <auth info>] <user> [<password>]
config [doveconf parameters]
director add|flush|map|remove|status
dump [-t <type>] <path>
expunge

Centos 6.6 procmail trouble

I have a 6.5 machine that had everything set up and working correctly (fetchmail, sendmail w/ starttls, procmail, spamassassin) but the MB cratered.
I bought a new machine, and installed Centos 6.6 and all is not well.

I used the config from the previous incarnation (via backups) for fetchmail (works fine), sendmail (works fine for sending via relay and tls), but procmail now refuses to pick up the correct MAILDIR location, and therefore won't deliver mail to the right place.

The example below is landing in /home/user/.spam_to_learn, NOT in /home/user/Maildir/.spam_to_learn
Maybe some other

Bind config question, centos 5.10

I must have something mis-configured in my bond setup.

slow i/o with a raid 50 on a 3ware controller

I have a raid 50 array on a 3ware controller. The box is running centos 6.5 and
the file system is ext4.

I'm going to try some other filesystems, but could anyone suggest any
alternative raid setups as well as stripe sizes I should try?

The old server uses the same controller on a centos 5.10 setup, using ext3, and
it performs much faster i/o. The old 3ware setup is raid 5.

-chuck

mail delivery question

I've built a new mail system with Centos 6.5, and I'm running fetchmail -
sendmail - procmail to maildir. I have all of this working at the moment.(I
know, postfix was the default, but for lots of other reasons, I switched, and
that isn't an issue, I don't think).

I am using dovecot as an imap server. Procmail won't update indexes during email
delivery, so I'm having some performance delays and lags when accessing the
emails via imap.

iptables question

I'm running fail2ban to attempt to block malicious brute-force password
dictionary attacks against ssh. They seem to be rolling through a block of ip
addresses as the source to defeat this kind of screening, so I've set some ip
addresses to be blocked in iptables.

SELinux issue?

I've recently built a new mail server with centos6.5, and decided to bite the
bullet and leave SELinux running. I've stumbled through making things work and
am mostly there.

I've got my own spam and ham corpus as mbox files in /home/user/Mail/learned.
These files came from my backup of the centos 5 server this machine is replacing.

The folder is owned by the user (the following is run as root):
ls -laF learned
drw-------. 6 user group 4096 Jun 10 03:35 ./
drw-------. 6 user group 35864Jun 10 03:35 ../
drw-------. 6 user group 4096 Jun 10 03:35 2004/
-rw-------.

procmail and dovecot

Does anyone know how to get procmail and dovecot to play happily together with
mboxes? I'm on Centos 6.5, fully patched.

I'm getting tons of lock timeouts which is killing performance.

I tried using dovecot's lda from procmail, which prompted many adjustments to
selinux, which I managed, but it still gives permission problems, and I haven't
succeeded in getting it to deliver mail.

Any guesses at all would be useful.

thanks,
-chuck